Dispositions (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Disposal Group Including Discontinued Operation Unclassified Balance Sheet Disclosures Abstract
Assets related to discontinued operations	$ 208,309		$ 208,309		$ 314,622
Liabilities related to discontinued operations	0		0		13,950
Discontinued Operation, Income (Loss) from Discontinued Operations Disclosure [Abstract]
Total revenues	3,923	19,311	12,206	45,301
Total expenses	1,771	13,191	7,321	33,234
Income from discontinued operations before gain on sale of real estate	2,152	6,120	4,885	12,067
Impairment losses	0	(2,493)	(842)	(4,007)
Income from discontinued operations	2,152	69,292	4,043	276,054
Retail Green Acres Mall [Member]
Discontinued Operation, Income (Loss) from Discontinued Operations Disclosure [Abstract]
Net gains on sale of real estate	0	0	0	202,275
Other Real Estate [Member]
Discontinued Operation, Income (Loss) from Discontinued Operations Disclosure [Abstract]
Net gains on sale of real estate	0	65,665	0	65,719
Retail Properties Segment [Member]
Disposal Group Including Discontinued Operation Unclassified Balance Sheet Disclosures Abstract
Assets related to discontinued operations	208,309		208,309		314,622
Liabilities related to discontinued operations	0		0		13,950
Retail Properties Segment [Member] | Retail CA Los Angeles Beverly Connection [Member]
Disposal Group Including Discontinued Operation Unclassified Balance Sheet Disclosures Abstract
Assets related to discontinued operations	208,309		208,309		208,458
Liabilities related to discontinued operations	0		0		0
Retail Properties Segment [Member] | Retail NY Hicksville (Broadway Mall) [Member]
Disposal Group Including Discontinued Operation Unclassified Balance Sheet Disclosures Abstract
Assets related to discontinued operations	0		0		106,164
Liabilities related to discontinued operations	$ 0		$ 0		$ 13,950